Property, Plant and Equipment, Net - Schedule of Components (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment, Net
Property, plant and equipment, net	$ 325,218	$ 313,418
Land and land improvements
Property, Plant and Equipment, Net
Property, plant, and equipment, gross	17,992	17,846
Buildings and leasehold improvements
Property, Plant and Equipment, Net
Property, plant, and equipment, gross	113,343	106,316
Furniture and equipment
Property, Plant and Equipment, Net
Property, plant, and equipment, gross	221,749	202,897
Property, plant and equipment in service, net
Property, Plant and Equipment, Net
Property, plant, and equipment, gross	353,084	327,059
Accumulated depreciation	(137,753)	(130,814)
Property, plant and equipment, net	215,331	196,245
Construction in progress
Property, Plant and Equipment, Net
Property, plant and equipment, net	$ 109,887	$ 117,173